Hi, not sure what's going on, but after some basic testing there seems to be no server at rhythm.noteworthycomposer.com.

This is something that only Noteworthy can tell us about.

FWIW the blog post was written in May of 2014, so the site may have been quietly shut down if no one was using it. The servers IP address in DNS is quite different to other Noteworthy Composer sites like www and forum.